1. Technical Field
The present invention relates to venetian blinds. In particular, to venetian blinds having individually adjustable slats and venetian blinds which do not have cord holes in the slats.
2. Background Art
Venetian blinds provide a convenient way to adjust the relative amount of light entering a room. However, due to their complicated structure, venetian blinds tend to be expensive. This is particularly true in regard to blinds which use decorative slats. It would be advantageous for the owner of venetian blinds to be able to conveniently change the slats on venetian blinds to accommodate changes in interior design. For example, to match changes in wallpaper, paint, etc.
In the area of vertical blinds, prior art attempts to replace vertical blind slats have been successful. Individual vertical slats are easily replaced because they generally are secured only at the top and do not have to accommodate cords for tilting or raising as do horizontal blinds. As a result, prior art systems are available which provide for easy replacement of vertical blinds. For example, prior art systems are known which use vertical blinds in which each blind contains a portion of a larger image. When the individual blind slats are assembled, the resulting blind displays a single image much like a mural. Because vertical blinds are easily replaceable, the image can be easily changed when desired. Other known vertical blind systems provide the ability to remove a vertical blind which is structured as a clear case with a replaceable insert for decorative purpose. These systems rely on the easy removal of vertical blinds which is based on the absence of cords.
While cosmetic replacement of vertical blinds is relatively easy, the replacement of horizontal slats on a venetian blind are relatively difficult and cannot be done by the user of the blinds without disassembly of the cords which extend from the headrail assembly through each of the slats. The prior art has failed to provide an easily replaceable venetian blind slat which permits a user to replace slats without tampering with the tilt or lift cords.
Another drawback to prior art systems is the extraneous light which penetrates venetian blinds though the cord holes in the slats. One prior art method of addressing this problem has been to position the cord holes such that when the venetian blinds are closed, the cord holes are covered by the slat which is adjacent to the slat with the cord hole. Of course, this method only works when the venetian blind is completely closed. If the blind is in any other position than closed, light will penetrate the cord holes. This method, therefore, only provides a partial solution to the problem of extraneous light.
Another attempt to address light penetration through cord holes has been in the area of pleated fabric shades. One solution in this area has been to manufacture pleated shades with dual fabric panels, each panel having a series of cord holes which are offset from the cord holes in the adjacent panel. The drawback to this approach has been the added cost of having dual panels. This method would not be feasible for venetian blind slats because the cost of the resulting blind would be too high.
While the prior art has recognized the problems associated with light penetration through cord holes, the solutions heretofore devised have been ineffective for venetian blinds because they do not work over the full range of slat tilting or are prohibitively expensive.
Another problem associated with prior art venetian blinds is the expense associated with custom building them to fit a particular window frame. The prior art has attempted to provide adjustable venetian blinds when used with rectangular window frames. However, due to the use of cord holes and the tilt and lift cords which are inserted through them, prior art designs are only suitable for rectangular windows. These solutions also are incapable of being adjusted to fit odd shaped windows because the tilt and lift cords require all of the slats to be moved in unison. As a result, they cannot be used with arched or angled windows and slat replacement for esthetic reasons is prevented by the presence of the cord holes and tilt and lift cords.
The prior art has failed to provide an adjustable venetian blind which allows a user to easily replace slats without removal or alteration of the tilt or lift cords; and adjustable venetian blind in which each slat can be individually adjusted can be adjusted for use with both rectangular windows or odd shaped or arched windows; and a venetian blind which reduces extraneous light penetration by eliminating cord holes.